MRI and PET Study of Cerebral Glucose Metabolism and Its Association with Perihematomal Edema Formation After Intracerebral Hemorrhage in Cats

PURPOSE: To explore the relation between cerebral glucose metabolism and perihematomal edema formation in cat Intracerebral hematoma (ICH) models by using magnetic resonance imaging (MRI) and F-FGD position emission tomography (PET). MATERIALS AND METHODS: Forty eight 3 years old male cats weighted 3.0±0.2kg were assigned into one sham operation group and seven ICH model groups for 2h, 6h, 12h, 24h, 48h, 72h and 120h observation, respectively. After being injected 1ml autologus nonheparinized blood into the thalamus by guidance of stereotactic apparatus all the cats were performed magnetic resonance imaging (MRI) and positron emission computer tomography (PET-CT) scanning at 2, 6, 12, 24, 48, 72, and 120 hours after intracerebral hematoma formation, subsequently, they were sacrificed for histology examination. RESULTS: The volume of perilesional edema on T2-weighted images did not increase from 2h to 12h after ICH, however it increased by 229.4％ at 24h, and peaked (by 273.5％) at 72h, thereafter it decreased. The pattern of T2WI intensity changes was the same as edema volume, there was a significant association between T2WI intensity and edema volume after ICH onset (P<0.05, r=0.97). The hyperintensive area of perilesional edema observed on T2-weighted images was also observed on diffusion weighted images (DWI), it has a higher apparent diffusion coefficient (ADC) value than in the contralateral white matter, and there was a significant association between ADC value and edema volume (P <0.05, r=0.95). The GD-DTPA contrast enhanced T1WI showed high intensity around clot at 24 hour. The F-FDG intensity in perihematomal edema tissues markedly reduced at 2h after ICH on PET images, and it reached the lowest level at 12h, then started to increase from 72h, at 120h it was comparable to control group. The change of SUV in perihematomal edema were consistent with those of F-FDG intensity, they were 0.97±0.07 (vs contralateral 1.33±0.15, P<0.05), 0.93±0.15 (vs contralateral, P<0.05), 1.83±0.155 (vs contralateral 1.86±0.14, P<0.05) at 2h, 6h, 72h, repectively. Low F- FDG intensity and SUV were also seen in bilateral frontal lobe and other areas of brain on FGD PET images. CONCLUSION: Perihemorragic glucose metabolism disorder was related to vasogenic edema formation, abnormal glucose metabolism may impair capillary integrity and increase blood-brain barrier permeability. So cerebral glucose metabolism has a close relationship to perihematomal, edema formation in cat Intracerebral hematoma (ICH). Intracerebral hematoma (ICH) has higher mortality and produces more extensive neurological defects than any other type of strokes. Perihematomal edema after ICH and the abnormal cerebral glucose metabolism are among the main reasons, however, the relations between them are complicated and poorly understood, although elucidation of their relations is of great importance in the treatment of ICH. In this study, we investigated the relations between cerebral glucose metabolism and perihematomal edema formation in cat ICH models using MRI and F-FGD PET.